1. Technical Field
The present invention relates to an image pickup apparatus, an image pickup element, and a method for controlling the image pickup apparatus. Illustratively, the invention may apply to a video camera for recording image pickup results constituting moving pictures, an electronic still camera, and a monitoring apparatus. This invention envisages varying the charge storage time or the frame period of image pickup means or the processing time of data compressing means in accordance with the processing time of the data compressing means so that when image pickup results are acquired at a high frame frequency for recording and transmission, the acquired image pickup results are compressed reliably.
2. Background Art
Heretofore, CCD (Charge Coupled Device) solid-state image pickup elements have been used in video cameras to acquire image pickup results at a 1/60 second field frequency through field readout. The image pickup results are compressed before being recorded to recording media such as optical disks. Such video cameras typically provide the so-called electronic shutter capability by controlling the charge storage time of their image sensors, whereby an object moving at high speed is imaged with high image quality.
In recent years, CMOS solid-state image pickup elements have been introduced for practical use. Illustratively, Japanese Patent Laid-open No. 2004-31785 proposes a configuration integrating a CMOS solid-state image pickup element with its peripheral circuits.
The CMOS solid-state image pickup element typically acquires image pickup results at transfer rates of as high as hundreds of frames per second. During image pickup, a more realistic effect than has been possible so far is typically gained using the CMOS solid-state image pickup element or a speed-enhanced CCD solid-state image pickup element providing image pickup results at high frame frequencies.
However, when image pickup results are acquired at such high frame frequencies, the amount of the data to be recorded and transferred increases dramatically. The process of data compression then cannot keep up with other processes, disrupting the image pickup processing as a whole.